Manufacture of steel



Warren dramas ATENT OFFICE.

ABRAHAM T. HAY, OF BURLINGTON, IOlVA.

MANUFACTURE OF STEEL.

SPECIFICATION forming part of Letters Patent N0. 399,612, dated March 12, 1889.

Application filed October 3, 1888. Serial No. 287,076. (No specimens.)

To all whom it may concern:

[ two and one-half per cent. \Vhen said sponge Be it known that I, ABRAHAM T. IIAY, a citil is added to the molten metal, a strong reac zen of the United States, residing at Burling- I ton, in the county of Des Moines and State of Iowa, have invented certain new and useful Improvements in the Manufacture of Steel; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My present invention is directed to the manufacture of steel, its object being to obtain with certainty a product of a high degree of strength, lionmgcneousness, and uniformity. The great value of such a product, especially in a steel desired for structural purposes, is apparent.

My invention consists in a method of treating the molten metal from which, the desired product is to be obtained, comprising a decarburization of the metal, (or partial deearburizatiom) a recarburization (where recarburization is necessary) and deoxidization of the same, and a purification or fining and alloying of it.

In order to make my invention clearly understood, I will proceed to describe, by way of example, a practical manner of carrying the same into eli'ect.

By means of an ordinary Bessemer converter, or other suitable appliance, I first desiliconize and decarburize the molten metal by the action of oxygen. I then by the use of spiegeleisen, or in other equivalent manner, recarburize to the desired degree and deoxidize the metal. It the open-hearth furnace be employed, the decarburization will be partial and the recarbnrization unnecessary. Thus far the ordinary process of steel-manufacture maybe pursued. To the steel thus producedpvhile in a molten conditioml add a ferruginous alkaline sponge-such as that described in my application filed September 26, 1888, Serial No. 286,430containing, preferably, one or more of the metals which are isomorphous with iron-such as calcium, aluminium, magnesium,manganese, chrome, and others-and one or more of the alkalies-such as sodium and potassium. For avery high quality of steel I may also add tungsten. Of such sponge I use by preference from one to tion at once takes place, the steel is purified from the seorize which are thrown to the top, and a steel alloy of a highly homogeneous and uniform character is produced, in which any phosphorus or sulphur within ordinary limits that may be present is so affected as not to deteriorate from the quality of the product. The steel is now cast into ingots and is ready for further working into rails, bridge shapes, axles, or other steel products.

The fining and alloying sponge may be introduced into the converter before pouring into the ladle, and where two per cent. or more of the sponge is used I prefer to introduce one-half of the same into the converter immediately after the silicon is oxidized and the other half into the ladle as the molten steel is poured into the latter.

I do not wish to be confined to the introduction of the sponge at the precise time or times stated, though I believe the mode described to be the best.

For the production of a high grade of steel of great tensile strength and elastic limit, I prefer to use for the purification a sponge containing calcium, aluminium, sodium, potassium, and chrome.

A practical form of a ferruginous isomorphous alkaline sponge suitable for the attainment of the above-described results is fully described and claimed in my application Serial No. 286330. One form of such a sponge may be produced as follows: Into a suitable retort or furnacc-such, for instance, as that described in my patent, No. 390,063t, dated October 9, 1888I charge a stock consisting of iron oxide-such as Pilot Knob ore of Missouriby weight, sixty-three (63) parts; coke, fifteen (15) parts; limestone, (preferably magnesian such as that of Joliet, Illinois,) seven and one half (7%) parts; aluminous substancesuch as scrap brick or cryolite-four (:ir) parts; carbonate of soda, two (2) parts; bichromate of potash, three-fourths (-5-) of one part; chrome in an oxide, one and one-quarter (1-3,?) part. This stock is fused, and,having been drawn off, forms the said sponge, which may be broken into pieces suitable for use.

In determining what form of the sponge to use, regard should be had to the composition of the crude iron stock and to the particular uses to which the steel product is to be applied, Whether for bridge members, railway- 5 rails, or other structural shapes.

Having thus described my invention, What I claim is The herein-described method of manufacturing steel, consisting in desilieonizing and I0 Wholly or partially decarburizing the metal, as

in a Bessemer converter or open-hearth furnace, and fining and alloying the molten steelby adding thereto a ferruginous alkaline sponge, substantially as set forth.

In testimony whereof I affiX my signature in I 5 the presence of two Witnesses.

ABRAHAM T. HAY.

Witnesses:

E. K. STURTEVANT, J. S. BARKER. 

